switch chip driver - Page 2

Let's try it again, from a simpler point of view.

Suppose the switch receives two broadcast packets on port 1, one
tagged VLAN 10 (call this '1,10') and one tagged VLAN 11 (call this
'1,11'). Then the switch receives two broadcast packets on port 2, one
tagged VLAN 10 (call this '2,10') and one tagged VLAN 11 (call this
'2,11').

I presume your intention would be packets 1,10 and 1,11 would come out
logical interface 1, tagged with VLANs 10 and 11 respectively. And
packets 2,10 and 2,11 would come out logical interface 2, tagged with
VLANs 10 and 11 respectively.

Is that a correct description of the effect you want?

Now, how can you get it?

Suppose you configure physical ports to ignore incoming VLAN tags.
Now, you can't tell packets 1,10 and 1,11 apart. So you have no way to
tag them correctly when you pass them to the operating system.

Suppose you configure physical ports to pass incoming VLAN tags. Now,
you can't tell packets 1,10 and 2,10 apart. So you have no way to
route them to the correct virtual interfaces when you pass them to the
operating system.

Since each of these four packets must be handled differently, you
would need to assign them four different tags in order for the driver
to tell them apart. However, there is no way to give them four
different tags -- you can only either pass the tag or set the tag.

And this is only one problem you would have trying to make this work.

DS

David Schwartz a écrit :


I didn't read any need for external VLAN tagging in Mark's posts.



What do you mean by "ignore" ? Replace the incoming VLAN ID with the one
associated to the port ?

My point is that his driver could not support VLAN tagging. It also
could not support hardware switching.



Replacing the tag is one way of ignoring it. Stripping it off is
another way.

DS